The present invention relates to a promoter region from Ashbya gossypii (=A. gossypii), to fungi which have been genetically modified with this promoter region, and to the use thereof.
A. gossypii is employed for the production of vitamin B.sub.2 by fermentation. It is desirable to extend the use of the fermentation technology available for A. gossypii by producing protein products using genetic engineering methods. An expression system for A. gossypii is required for this purpose. Systems of this type have already been described for some higher ascomycetes such as Aspergillus niger (Rambosek and Leach, CRC Critical Reviews in Biotechnology 6 (1987), 357-393). By contrast, to date no experience in the area of genetic engineering is available with the hemiascomycete A. gossypii, which is the sole representative of its genus.
An essential component of a system for the expression of genes which code for a required product is the so-called promoter region which is composed of
1) a functional promoter which is indispensable for transcription of the gene, and PA1 2) the 5' non-coding region (between promoter and translation start) which is necessary for translation after transcription into mRNA. PA1 a) by cloning the gene for translation elongation factor EF-1.alpha. (TEF gene) from A. gossypii including adjoining DNA sequences and subsequently cleaving, PA1 b) by fusion of A. gossypii DNA fragments to an open reading frame of a promoterless gene which is selectable in A. gossypii, isolation of strongly expressing transformants and subsequent selection of the TEF promoter, PA1 c) by chemical synthesis using known methods.